CATOOD6RHAEP0O398 D6R all the sudden runninh alot warmer than normal. Coolant level was a gallon low. Added coolant and replaced radiator cap as the old one had rotten rubber. Will run 2 or 3 hrs and slowly creeps higher to just shy of the red. Can let machine idle and it returns to normal in 3 or 4 minutes. Still losing fluid, but I can't see a leak anywhere. Does the water pump have a weep hole and could it be leaking and not be seen? What you giys check first?
If you keep the engine at about half speed how quickly does the coolant temp fall.? If you are losing coolant the first step should be to find out where it's going. You'll need a radiator pressurizing pump and get some pressure into the system when the tractor is cold to identify where the leak is.
Be sure to check the oil in the engine crankcase for the presence of emulsion in the oil.
Any bubbles in the rad. (cap off) with the engine running?
Still could be filling up all the passages that had air. How rotted or sand blasted is the radiator?